Design And Realization Of Grating Auto Testing Instrument

The selected subject gives a general design of the grating auto testing instrument, by using the characteristics of orthogonal A and B signals output by optical encoder and symmetrical black and white linear transmission grating bar, and analyzing the means of the high electrical level of signals change to number of counter pluses. Then, the key technologies in the realization of the grating auto testing instrument are introduced particularly. In the design, we select the HEDS-9730Q optical encoder of Agilent corporation to be the test component, and use VHDL to realize the part of collection of test data in the CPLD chip EPM9320LC84-15 of Altera corporation. The test data are transferred to the console in PC by using the serial communication of MCU AT89C52. We use a FIFO to realize the speed matching between collection of test data and serial communication. Microstep driver of stepper is programmed to reduce the noises and to make motor run steadily. Signals of self test realize the function of self test of the grating auto testing instrument. After detail design and examination, we reached the design requirements, and realized a grating auto testing instrument.